Contagion Engine (Scars of Mirrodin)

When this artifact enters, put a -1/-1 counter on each creature target player controls. {4}, {T}: Proliferate twice. (Choose any number of permanents and/or players, then give each another counter of each kind already there. Then do it again.)

NM - $10.00
LP - $8.00
MP - $6.00
HP - $4.00
DMG - $2.00